In order to produce high-quality products, we must first operate the twin-screw extruder in strict accordance with the operating procedures, and at the same time, we must regularly maintain and maintain the extruder unit.
a. Preparations before driving
For a co-rotating twin-screw extruder, check that the screw assembly is correct before starting. After the screw is installed, turn the screw slowly to make the two screws rotate. If it is easy, it means that the combination is correct. If it is difficult or the disk does not move, you should remove it and reassemble.
For meshing twin-screw extruders, be careful not to mistake the positions of the two screws when loading the screws. If the material is added to the feeding port after driving and the material is not transported forward, the screw head will be on the machine head, and the current will increase. In this case, stop the machine immediately, remove the machine head, and reload it in the correct position. .
Before driving, check whether the circuit wiring of each part of the machine is correct; whether the cooling system of the barrel screw is normal and smooth; whether the drive system is normal, whether the lubricating oil level is normal, and whether the oil circuit is smooth; whether the metering and exhaust system is normal; Whether the connecting bolts are tightened.
Before driving, the part of the extruder that needs to be heated should be heated, and the bottom of the hopper and the cooling part of the screw should be cooled in the cooling medium. When the set temperature is reached, it should be kept for 10 minutes to make the temperature of the screw and barrel uniform.
b. Points for attention when driving and stopping
For pellets, metering should be added to prevent overloading; for powders, overflow feeding can be used, paying close attention to whether the overload is. When driving, add a small amount of material first, and keep the feeding balance. At this time, pay close attention to the pointer of the torque meter. The speed of the main screw should rotate at a low speed. After extruding the material from the die and introducing the traction equipment, slowly increase the screw speed, and then increase the amount of feed until it reaches the set value.
Stop feeding before stopping, and the screw of the host machine runs at low speed to discharge the material in the screw cleanly. For the opposite-direction twin screw, when the standby head no longer discharges materials, remove the head, pull out the screw, clean the screw, head, and barrel while it is hot, and then reset it for assembly and use it next time. If special cleaning materials are used, it is not necessary to pull out the screw for cleaning. For co-rotating twin screws, if the screws need to be reassembled at the next extrusion, the components of the screw must be removed while hot, thoroughly cleaned, and then reassembled according to the new screw configuration. The barrel bore and head should also be cleaned.
When cleaning the head or screw element, use a steel knife, copper brush, paraffin, gauze, etc.
c. Repair and maintenance
Regular maintenance should be performed in accordance with the instructions attached to the extruder when it leaves the factory.
It should also be maintained and maintained normally. If the empty car is not allowed to avoid wear of the screw and barrel; if it is not operating normally, it should be stopped immediately for inspection and repair; prevent metal or other debris from falling into the hopper. If the head is equipped with a pressure sensor, it should be carefully assembled and disassembled. Do not hit or scrape the accumulated material on the diaphragm of the sensing part with a hard object. Wear a protective sleeve when not in us